I. Field of the Invention
The present invention relates to radar systems. More specifically, the present invention relates to a novel and improved system for identifying signals transmitted or received on the sidelobes of a radar system antenna.
II. Description of the Related Art
In the past, communication systems have been developed that label the signals transmitted on the sidelobes of the communications system antenna while the mainbeam transmitted signals are not labeled. A communications system receiving the transmitted signal can determine whether the signal, as received, was transmitted on the mainbeam or sidelobes of the transmitting system antenna. The signal transmitted on the sidelobes of the transmitting antenna contains the labeling and if the received signal contains such labeling it is detected. The detection of the labeling in the received signal is indicative that the received signal was transmitted on a sidelobe of the transmitting antenna.
It is also known to use in communication systems the technique of labeling signals received on the sidelobes of the receiving system antenna. The signals received on the mainbeam of the receiving antenna, however, are not labeled. In the receiving system, if the signal is received on one of the antenna sidelobes it is labeled and the labeling is detected in the receiving system. Detection of labeling in the received signal is, therefore, indicative that the signal received was received on one of the sidelobes, rather than the mainbeam, of the receiving system antenna.
Communication systems for discriminating between signals arriving on the mainbeam and the sidelobes of a receiving antenna along with communication systems for discriminating between signals transmitted on the mainbeam or transmitting antennas are known. Examples of such systems are disclosed in U.S. Pat. No. 4,250,506, entitled "Sidelobe Discriminator" issued Feb. 10, 1981 in the name of William F. McNaul, one of the inventors of the present invention, and assigned to the assignee of the present invention; and U.S. Pat. No. 4,266,2276, also entitled "Sidelobe Discriminator" issued May 5, 1981 in the names of William F. McNaul and Paul R. Eberhardt, both inventors of the present invention, and also assigned to the assignee of the present invention.